Alcohol fuels are known to have a high octane number, which inhibits autoignition (also known as knock; knock is self ignition of end gases ahead of the flame front occurring after spark firing) in spark-ignited internal combustion engines. This allows an internal combustion engine to be operated at a higher compression ratio and/or a higher level of pressure charging in the intake system. However, alcohol fuels are prone to pre-ignition, which is a combustion phenomenon occurring prior to spark plug firing. It is believed to be a surface phenomenon where the fuel comes in contact with a hot spot in the combustion chamber, such as the spark plug tip, a bit of carbon deposit, the piston top, and exhaust valve, and initiates a flame front. This can lead to damage of the engine because it can become a runaway problem. That is, when pre-ignition first occurs, the early combustion leads to very high in-cylinder temperatures and high heat transfer to combustion chamber surfaces. Then, in succeeding cycles, pre-ignition is even more likely and happens earlier in the compression stroke making the temperatures even higher. If left unchecked, high temperatures can lead to engine parts melting and complete failure of the engine. It is known in the art to undertake measures to mitigate pre-ignition.